.Code: Select all
; SI -> address of font in DS (8 bytes of data)
; DI -> address in video memory (in ES) to start writing
; destroyed: ax, cx, dx, si, di
printchar:
mov cl, 8 ; 8 character rows
loop1:
lodsb ; load font data
mov dl, al ; move data
mov ch, 8 ; second counter in ch
loop2:
shr dx, 1 ; pop a bit into CF
sbb al, al ; load al with 0 on background, ff on foreground
and al, 15 ; use color #15 for foreground
stosb ; poke a byte to video memory
dec ch ; decrement second counter
jnz loop2 ; loop if more
add di, (320 - 8) ; go to the next scanline
dec cl ; decrement first counter
jnz loop1 ; continue with next scanline if not done
ret
Code: Select all
org 100h ; com file
mov ax,0013h ;set graphic mode 13h
int 10h
mov ah,13h ; request display string
mov al,00 ; set sub function
mov bx,0x0064 ; set attribute and page number
mov cx,12 ; number of letters
mov dl,1 ; screen colum
mov dh,2 ; screen row
mov bp,string ; address vof string es:bp
int 10h ; call int
xor ax,ax ; wait for keypress
int 16h
mov ax,0003h ; set text mode
int 10h
ret ; return
string: db "Hello world!" ;string
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